This was an interesting issue that came up in one of my games. I believe that if the reavers win a challenge while attacking alone then you do location claim even if the opponent has Twist of Fate revealed, as their location claim is a mandatory passive. However, my opponent thought that since they were both conflicting passive effects (both claim replacement) that the first player would be able to choose which one occurred (i.e. location claim, or a choice of the 3 normal claims). What's the verdict?

They're conflicting claim replacement effects rather than conflicting passives, but the outcome is the same - the first player decides the order they occur (with the 2nd effect being the claim that is applied)